Technical Field
The present invention relates to a touch sensing method. More particularly, the present invention relates to a mutual capacitance touch sensitive sensing method.
Description of Related Art
Touch sensitive panel is one of the major human-machine interfaces nowadays, especially the mutual capacitance touch sensing panel that can provide better sensing accuracy. Please refer to FIG. 1, which is a perspective view of a conventional mutual capacitance touch sensing system 100. The touch sensing system 100 includes multiple first electrodes (or driving electrode lines) 120 and multiple second electrodes (or sensing electrode lines) 130 which are disposed in a touch sensing region. These first and second electrodes 120 and 130 are both connected to a sensing apparatus 110. The sensing apparatus 110 transmits the detected touch event information to other circuits or modules (e.g. the main processor of a computer system) via other interfaces.
Several areas, where the first electrodes 120 overlap but are not in contact with the second electrodes 130, exists between the first and the second electrodes 120 and 130. During one scanning cycle of the touch sensing region, the sensing apparatus 110 sequentially charges the first electrodes 120 to send driving signal, and then charges the second electrodes 130 to conduct touch sensing. When a certain first electrode 120 is charged and the electrical change is detected on a certain second electrode 130, the sensing apparatus 110 could then determine that the touch event takes place in the area or near the area where the certain first electrode 120 overlaps the certain second electrode 130.
In order to scan all the areas in the touch sensing region in one scanning cycle, each of the first electrodes 120 must be charged once sequentially. Assuming that the second electrodes 130 conducting touch sensing simultaneously requires time t, and the number of the first electrodes 120 is M, then the total time of one scanning cycle of the touch sensing region would be M multiplying t. Meanwhile, due to the users' increasing requirements for touch sensing efficiency, the sensing apparatus 110 has to respond to the system more and more frequently. As a result, there is a demand in the market for a touch sensing method and system that could decrease the time for scanning the touch sensing region and increase the touch report rate.